At my favorite drugstore, comic books used to cost 10¢ .
(It wasn't yesterday, or even last week. In fact, the drugstore
was burned to the ground during the riots in 1964, and never
rebuilt. But I digress.)
Normally, my parents only let me buy one comic book at a time.
But before I left for summer camp, I could empty my little piggy
and spend it ALL on comic books, all at the same time ! That
was as much fun as the whole 2 weeks at camp !
I emptied my little pig. I had 67¢ in there. I headed for the
drugstore. For the whole rest of the afternoon, I stood at the
magazine rack, carefully deciding on my selections.
How many comic books did I buy ?
What was the remainder ? (How much money did I have left ?)
Option A:
3 ÷ 4 = Quotient 0 Remainder 4
Option B:
12 ÷ 3 = Quotient 4 Remainder 0
Option C:
15 ÷ 4 = Quotient 3 Remainder 3
Option D:
4 ÷ 15 = Quotient 0 Remainder 4
-1 is less than 0, so you use the first equation:
3(-1) +2 = -3+2 = -1
f(-1) = -1
For 0 use the 2nd equation:
3(0) + 4 = 0+4 = 4
f(0) = 4
For 2 use the 2nd equation:
3(2) + 4 = 6+4 = 10
f(2) = 10
